Go to this site on you phone's browser, then scroll down to the bridge apps section and find the one for your phone's OS version.

This is mostly for at&t subscribers, because at&t in their infinite wisdom only allows bridge software with the bridge browser disabled to be installed on the phones of customers who do not have a tethering data plan. This wonderful person has graciously provided the complete bridge app for those of us who would not otherwise be able to get it. I'm not sure if there's any difference between these and the versions of the bridge available to Verizon customers.